Abyss depth needs harder scaling, so this stops even more
nearly harmless monsters from trying to be threats
past the initial Abyss:1 balance. Most noticeably,
this makes the large and small abomination exchange
less extreme so that earlier floors of abyss still get
quite a few more large abominations and less smalls.

Also, cut the scummable pearl dragons, boring tengu,
and move some weight over from ynoxinul to blink frogs.